Both the NY Times and the Washington Post have rather extensive obits on the death of Morton Sobell (I’ve copied and attached to this email the Times obit).
I have actually had two points of contact with Sobell over the last 30 years or so. First, having lived in San Francisco and been assigned to the FBI office there I had occasion to visit Alcatraz Prison more than once and saw his prison cell. The staff has placed a photograph of him and a short bio on the time that he spent there. In addition, at the VENONA conference in 1995 I introduced myself to him and ask him to sign the book that was given out to attendees at the conference. My business partner at that time, David Major, was irate when he found that I had obtained Sobell’s autograph, saying: “you let that Commie sign your book?” I replied that he was a historical commie and that I was collecting autographs of all of them I could find. Sobel was happy to sign but unwilling to discuss any role he had in the Rosenberg espionage network. I thought that was too bad because he could have put in perspective the pressures and motivations of the time which motivated him and others in the cell to commit espionage on behalf of our WWII ally, the Soviet Union.
Morton Sobell, Last Defendant in Rosenberg Spy Case, Is Dead at 101